The field of the invention relates generally to conditioning sensor information, and more particularly to systems and methods for use in conditioning a signal from a speed sensor.
In a machine with at least one rotating device, such as a rotating shaft, it may be beneficial to include a speed sensor in the machine to obtain a reference mark and timing information. A speed sensor provides phase, speed of rotation, and/or rotational position information. Such information may be used to determine whether the machine, and in particular, the rotating device, is operating normally.
Known speed sensors, to do this, are mounted at a fixed location near the rotating device. The rotating device includes a marker affixed at a given location along a circumference of the rotating device. As the marker rotates past the speed sensor, the speed sensor outputs a corresponding signal indicating that the marker has passed the speed sensor. In some implementations, multiple markers are placed at different locations along the circumference of the rotating device, and the speed sensor outputs a signal indicating that multiple markers passed the speed sensor every revolution. A known marker may be, for example, a notch or projection in the material of the rotating device. The speed sensor includes a transducer that outputs a signal that is representative of the nearness of the marker to the speed sensor. The signal is output as an analog signal and often includes noise due to vibration of the rotating device, electrical noise, and noise due to non-homogenous properties of the material of the rotating device. Accordingly, additional analog and digital circuitry is often coupled to the speed sensor to eliminate the noise and vibration and to convert the analog signal into a digital signal. However, such analog and digital circuitry generally includes multiple discrete components that increases the costs and complexity, and that increases the amount of space necessary to monitor the machine.